Note: Due to receiving many questions, the
Sony BP-2EX battery might be available at
this link.

As
a world traveler, sitting within the "tuna can" for over six hours can
be a mind numbing experience. Other than the lousy airline food and ever-declining
quality of onboard
service, bringing your own entertainment during a trip is a must. Also,
those who are allowed to enjoy music at work will find this review enlightening. Portable systems must be just that,
completely portable and therefore mandate the use of headphones. So what is an
audiophile to do with all the junk at mass market stores?

Any audiophile worth their salt would never choose mp3 or other
lossy compression scheme devices. "The iPod" shouts the Apple Dumpling Gang
from the back of the room. No thank you. While it is indeed a great mass-market
product, its music reproduction abilities are far behind what is truly
possible. As for portable DVD units, tried a few and feel they were just ok with
higher resolution digital discs, yet most audiophiles have only one real choice. We
are stuck with the decades old compact disc (CD) and finding a good set of headphones.
As for myself, decided to make this a completely no-holds-barred affair. Have
been seeking the very best there is within the world and this meant everything
and anything was fair game. If you can beg, borrow or mysteriously acquire it,
then it was "all good to me". My goal is to enjoy the music and find a
way to make a portable system that audiophiles would gladly approve.

Back To The Future!After much listening and playing the musical credit card game, i eventually realized that there is not a single
new portable CD player, not a
one worth owning. They either force you to use their built in lossy compression
to make a 45 (or whatever) second anti-skip or have other deficiencies that make
them sound, frankly, like sandpaper on a metal grate. With this in mind i choose
to use my old, yet said to be good Panasonic SL-CT470 as representing today's
best unit. Having been in the portable and gadgets market over a decade longer than Maxim,
Stuff, and any other such magazine has been around; my vast
knowledge of the past would be of immense help today. In fact i was the
technical editor of a magazine called Gadget World nearly a decade ago!
This was many years before other types were even a glimmer in their parent company's eye.
And the true finalists
are:

Sony D5, Sony D-25, Sony D-555, and Panasonic SL-CT470

Many of you old timers will remember the Sony D-5. This unit
comes from my personal stash of historic goodies. This, my friends, is the
original world's first portable CD player with a date code of December 1985.
Eventually i graduated to the Toshiba pyramid-like unit with wireless remote and
Sony D-88 (words smallest CD player), yet the D-5 won its way into my heart as a
way to feed into my then drum set's mix board for monitoring/concert breaks/jam
sessions and portable music enjoyment. The D-5 employs no oversampling and probably
one of the industries ugliest Brick Wall filters man ever conceived.

Basically, a Brick Wall filter ensures the
digital to analog decoder's intermodulation noise does not reach the analog output stage.
This filter also can add various distortions like phase shifting. Basically it
is used to block the DAC's noise from interfering with the analog signal. Due to having a low 44.1kHz sampling rate
chip, a very steep filter was needed. It is a apparently necessary evil akin to death, taxes, and the British class
system. This is partially why consumers quickly saw 2-, 4-, and 8-times
oversampling systems as a less aggressive filter could be employed. Then came
various hybrids (8-bit DAC for upper, 1-bit filter for last/lower 8 bits) and
eventually 1-bit systems arrived on the scene.

Getting back to the D-5, is it about as basic as they come. It
offers the usual play, stop, forward, back, etc. No Super Bass, no skip
protection, no hard drive, no mp3 decoding... You get a CD player that works...
even 18 years later. These were not disposal units mind you like the
$39 Super Save
Mart specials of today. i paid somewhere around $400 for this unit. The
case is mainly plastic and the overall feel of the unit is solid.

Next up is the Sony D-25 that was a few generations after the
D-5. With a date code of August 1989, this was truly one sexy portable CD
player. The all-metal case has some lovely curves and lines while the entire
unit is about as solid as they ever made portable CD units. The unit is very
slim and small, being about two CD jewel cases stacked atop each other. A nearly
9-Volt sized BP-2EX rechargeable battery (replacements may be available
for sale here) fits within the unit to provide
approximately three hours of musical bliss. The Sony D-25 also enjoyed the
technological progress of 4-times oversampling, yet still no bass boost or other
more modern features. The 4-times oversampling meant a less evil Brick Filter could
be employed within this design. Still, the D-25 is your very basic portable CD
player. Sony decided to place most of the controls on the upper right of the
D-25 while small front buttons allowed for the usual time/index/memory/etc. features.
Like the D-5, volume control was via a small potentiometer and not
electronically controlled like many units on the market today. Purchased this
unit recently from an EBay auction on a spur of the moment. Never intended to buy this, yet while
shopping for the Sony D-555 i realized i have a soft spot in my heart for gear
marked "retro", "classic", and "old school". $50 later
and the EBay auction was won by Yours Truly.

It's Good To Be KingIn 1990 music lovers were able to experience what many still
consider to this day as the end-all be-all portable CD player. Sony's D-555 hit
the scene with more features and tricks than you could shake a stick at... and
why i own two of these puppies.

Besides having a good (at the time) 16-bit, 8-times
oversampling, it also was one of the first units to offer dual digital to analog
converters (one per channel) within a portable CD player. While my years older Toshiba
unit had a digital output, this very rare feature was also on the Sony D-555.
Please keep in mind we are talking optical TOSlink, yet a portable with digital
output was a "high-end" premium feature back in 1990. It makes sense
my old Toshiba had optical digital output as TOSlink stands for Toshiba Link.

The D-555 also heralded the use of Digital Signal Processing
(DSP) in a portable unit. While a big yawner here in 2003, in 1990 DSP was like the Almightily
herself came down from heaven to grace the digital realm. While you could only
enjoy one DSP effect at a time, you were offered an impressive five bands of
digital equalization (63Hz, 250Hz, 1kHz, 4kHz, and 10kHz), or Surround, or Bass
Boost, or not-so-glorious DSS (Digital Dynamic Sound). DSS is basically a dynamic compressor so
that overall dynamics are more even. This helps boost very quiet passages and
makes them louder and, hence, more audible in noisy environments. The point here
is that the D-555 had features only dreamed about in 1990 as we must remember that CD
appeared to the masses in 1983. Only 7 years later we have 8-times oversampling
and DSP within a portable player!

More good news is that the D-555 is almost entirely metal
encased except for the top and front displays. You can see above the effect MODE
button, EQ adjustment button, EFFECT - +,and electronic volume control. That's right, no
potentiometer to get in the way of the music! She is 100% digital, all the time
with the D-555! The usual back, forward, stop and play buttons plus OPEN appear
on the lid. The front of the unit had various buttons to check remaining time
and change play modes. Many of us used the programmability of CD players back
then to check remaining time as we would make cassettes of our favorite CDs.
Automotive CD players being priced in the stratosphere so cassette was still
King! Add to that the early
generation car CD players would skip quite often during speed bumps and the
like. My first D-555 was used and abused through various road trip gigs and DJ
work. She paid her dues over and over again and is now nearly dead. Bought
another unit on EBay a while back and she seems virtually band new. Due to it
being a cult classic, the D-25 was bought for only $50 while the D-555 cost me
around $250. Yes, $250 for a nearly 13 year old portable CD player! The
D-555 was no cheap unit at the time when it was brand new, retailing at around
$400 or so as i recall.

New Kid In TownRecommended to me by various people, they said to me
"Steve, the Panasonic portable CD players are the best out there. They
sound great." So like a deer caught in a car's headlights i bought it
about a year or so ago sound unheard. It was ok, i guess.

The Panasonic SL-CT470 has all the usual features. Bass boost,
anti-skip, preset EQ curves... While it will not play MP3 files, it has all the usual
features that make up the average unit of 2003. Unlike the Sony D-25 and D-555, the D-5
and Panasonic SL-CT470 are purely plastic encased. Not much to report here
really, just the usual dreck thrust upon the unsuspecting public.

Showdown!So how do these four top contenders stack up? Well sit right
back as the result surprised me! This was a trip though time... but also where
newer is not necessarily better!

At the top left we have the Sony D-5. The upper frequencies
sound hard, with cymbals and high-hat apparently rendered like a chain
saw cutting through a pine tree. Bass is barely acceptable and muddy with a midrange
makes you want to run away as fast as possible. It is that bad. Odds are the Brick Filter and
early digital technologies are showing their age to the more modern and refined units. Still, the D-5 is
the world's first portable CD player so i keep it here as a museum piece. i'll
skip the D-25 and D-555 for now and move on to the virtually new Panasonic SL-CT470.

The SL-CT470 is not a bad unit per se, it just does nothing
well. Bass is lackluster and bass boost just makes things muddy. The midrange is
ok, if you like your music to sound sterile. As for the uppermost frequencies,
it is a bit hard like an anvil banging on a steel plate. Not chain saw bad like
the D-5, more like anvil banging bad. Probably great for
those who enjoy house, trance, and other synthetic music, yet for audiophile
recording of acoustic music you are better off using this unit as a paperweight. Maybe those consumers who enjoy lossey
compression MP3 find the Panasonic a great unit, but those of us with audiophile
ears know better. Ok, it is not that bad (close to it
perhaps), yet when you listen to virtually any decent home CD player with headphones...
you get the drift. Nearly the same comments could be said for many other modern
portable equivalents. Sorry and all, not a great one in new CD player bunch and it matters
not if you are using batteries or the included power supply. So this leaves us
with two nearly decade-old units.

When Is A Legend Over Rated?The Sony D-555 does indeed live up to the hype. For a portable
unit, let alone one that is nearly 13 years old, it reproduces music with grace
and style. While my headphones (more on this later) need virtually no
equalization, the rare recording may need it and the D-555 has a built-in five
band digital equalizer. Bass boost works quite well while
the DSS did wonders for enjoying properly recorded classical music while i was
flying from the United States to Frankfurt. While some digital volume controls
of years past accomplished this task by reducing the bits, i somehow doubt the
D-555 does this. Why? Because this is very early technology and i do not believe
that type of capability was available. Of course i could be wrong, yet the Sony
D-555 easily blows away the Panasonic SL-CT470 and Sonly D-5. What you receive
is good resolution, depth, smooth frequency response, and very usable bass
definition. The midrange lacks the ultimate smoothness while overall,
harmonically speaking, the unit could use a good dose of Digital Demon removal.
In fact the D-5 was Satanic in this regard with the Panasonic not too far
behind. The D-555 was more refined yet heaven-sent it was not. i paid a very
pretty penny ($250) on EBay and realizing there is already one here, it was more
to have a known good working unit as Sony can no longer repair these old units.
But the real surprise is...

The Emperor Doesn't Need Cloths!Bought on a whim due to my love for things "retro" and
"classic", the D-25 arrived at my home... and into my unsuspecting
hands and ears. Did not really expect much from the D-25 really. Owned a D-10 (predecessor)
and D-25 back in the day and they were good. Only after plugging in and listening
to the D-25 did my brain flood of memories.... Good ones! You see my friends,
having not been happy with boom boxes of the time i decided to make my own
using Sony APM self-powered speakers. A Case Logic 30 CD case was the main body
of my invention with the D10 / D-25
for source duties. This portable system was all Velcro'ed together and was the
best damn boom box on the market to my ears. Virtually living on Ft. Lauderdale
and Hollywood beach in Florida to get an awesome tan meant i needed a great portable sound system. Back
then i always preferred loudspeakers to headphones. Only during recording studio
gigs was i forced to wear headphones.

Getting back to the Sony D-25, this unit is so far ahead of anything else out there that it, in fact, challenges some of the better
audiophile home CD players of today! Now i realize this is a very strong
statement, and one that is not made lightly as my loyal readership knows that i
rarely make such sweeping statements. In fact i would award this CD player the best
damn thing since sliced bread, yet it is made of virtual Unobtanium and if you can find a working, good condition D-25 it will be a rare day indeed. So why on
her Almighty's green Earth would i go out of my way to recommend this unit?

Because
my friends, until you have one in your possession all other portable CD players
(including the legendary D-555) will only be a shadow of what is truly
possible. You are simply fooling yourself thinking the Panasonic or iPod are the
best thing since sliced bread. Heck, other units are akin to a Ford Pinto in comparison! Now
a Pinto may be a good car and all, yet a Ferrari it aint! So what does the D-25 sound like? Stop
the teasing and start the pleasing!

I -- Smiling Next To You
In Silent LucidityIn a word, gorgeous. To expand on this, glorious. To expand
further, very defined and tuneful bass with highs that not only sound good, they are very smooth and clean. As for
the midrange, at times i wonder if there isn't some small mesh plate 300B hiding
within this metal case somewhere. Add to this incredibly realistic harmonics and
a
front soundscape so deep that it makes me rethink the possibilities. The
right/left width may be
a bit narrow compared to the best home units though. This may be due to using a
single chip for both channels. The truly remarkable part, as if the aforementioned
bits were not impressive enough, is the sheer layers upon layers of resolution. Both macro and micro
resolution are combined with wonderful dynamics. Must admit, the Sony D-25 is not
the last word dynamically, yet am using the stock power cord and brand new rechargeable
batteries from Sony. Yes, the rechargeable batteries are still available for
about $35 each. Is using the unit on batteries better than power? It is too close to call really.
Maybe one day i will get a Super He-Man power supply for the D-25, though for this review
only stock units are used.

Disc after disc i sat there
in awe. Not just through headphones,
but also within my reference system. In fact it is within my reference system
where the soundscape depth and amazing 3D ability shines as headphones leave a
bit to be desired in this department. The D-25's inner resolution is amazing using my new reference headphones (see below to learn more). After a few days it
finally hit me what might make the D-25 so good.

Look at the close-up of the D-25's lid. Digital tweakers
and those in the know will quickly realize the 4-times oversampling text. It is
no secret that many audiophiles out there swear by this system over virtually
anything before or after it. Not the hybrid 8-bit/1-bit systems, not the 1-bit
systems, not the mega-resampling... just a basic 4 times oversampling
system. We must also understand that there is very little going on within the
D-25. No mega-bass, no DSP, no EQ, no anti-skip... not even digital volume control!
Here is a purpose-made unit with potentiometer-based volume control all wrapped
in a metal case. The case should not simply be dismissed as audio inventor/guru
Ken Ishiwata of Marantz and i were discussing the Sony D-25 and how he feels the
case of a unit (like his tweaked out Marantz units) plays an equally important role
in the ultimate music reproduction abilities.

i could go on and on with how amazingly the Sony D-25 is at
reproducing music on compact disc. It truly redefines what is possible, and
sadly, nearly impossible to find on the open market. Seek and ye shall find.
Sometimes the fun is in the hunt, though when you finally find one the fun is
in the listening! Listen and believe!

Best Portable 'PhonesNotice the title is not "Best Portable Headphones".
Why is that you ask. Because any headphone worth listening to is (generally) far from
portable. The well-received Sennheiser HD600 are so large and obtrusive that,
unless you are a true fanatic or insane, they are not a portable device for
those on the move. Grado you say? Not when trucking around the way i do as a
mover and shaker. After a long and careful search my travels lead me to the new
Shure E5c in-ear monitors.

My exposure to in-ear monitoring is a long and torrid affair. It
started nearly two decades ago with various Sony "fontopid" earbuds. These were small round units that were simply small encapsulated
drivers. One driver per channel/ear with amazingly thin and delicate wires attached.
Headband need not apply. You
placed the unit horizontally within your ear and a sponge-like cushion around
the small driver assisted
in holding the unit in place. As some consumers did not like placing things
within their ear, Sony also offered vertical units that had a more normal
headband (see yellow headphones below). The photos below, by the way, show Sony's newest offerings.

The in-ear fontopid (as seen left) was an amazing accomplishment of
its time.
Sony had many different versions and qualities thereof over the years. It was not
until Panasonic came along and eventually offered a dual-driver unit. This was
sometime around 1990. It was a large affair with a separate tweeter and bass
driver "fontopid" with a black and gold colored motif. The unit was
quite large as the bass driver was squarely outside your ear. The unit also had
porting to further increase the sound quality (as we find ported loudspeakers of
today, yet on a very miniature scale of course). Back in the day i was a fanatic
collector of such devices and the Panasonic was far and above the sound quality
Sony offered at the time. In fact i would still have the Panasonic dual-driver
units, yet they were stolen when my then car was towed.

As we fast forward to today, the quality of in-ear monitoring
has vastly improved. Various devices from both consumer and professional audio
companies abound. Most audiophiles are familiar with the Etymotic ER-4S (as
reviewed here by Todd Warnke) and Etymotic ER-4P (as
reviewed by Chris Boylan) as they have been touted by many as a great
alternative to other types of headphones. Always on the lookout for the best of
the best, it was with great joy that the new Shure E5c came along.

Unlike small "bud" units, the Shure E5c is a larger
affair and to my knowledge is the only new, two-driver unit on the market today
(like the Panasonic was during it's time).
A small tweeter and slightly larger bass driver are all encapsulated within a
single housing. To save some time and questions, here are some excerpts from
Shure's website:

How are in-ear earphones different from other headphones?
The primary difference is their listening position — where they are worn in relation to your ear. Headphones generally enclose your ear or rest on top of it. Regular earphones (like the earbuds often packaged with CD players) sit on the outside of the ear. In-ear earphones are different. They are designed to fit inside your ear canal, where they create the isolated listening area responsible for their unique acoustic properties.

Why is isolation important?
In-ear isolation makes it possible to hear greater detail at a lower volume than is possible with earbuds or most headphones intended for portable use. Lower-volume listening means less fatigue over extended periods, and is safer than trying to overcome background noise by turning up the volume. This makes isolating in-ear earphones the ideal choice for commuting, travel, exercise, study, or work — any activity where you desire portable, hi-fidelity sound.

Is isolation different from noise cancellation?
The isolating seal created by an in-ear earphone physically blocks most frequencies of background noise and is a simple, natural form of noise attenuation. Active noise cancellation "headphones" are generally larger, heavier and battery-driven. The active cancellation process negates selected frequencies through a complex process that can even introduce unwanted artifacts into the resulting audio. The natural noise attenuation properties of a properly fitted in-ear earphone can rival or exceed the performance of even the most expensive active noise cancellation alternatives.

So basically you can now understand the advantages of in-ear
monitoring. Less fatigue, more direct sound, and a lowering of external noise.
One advantage not yet discussed is that you can have custom ear pieces made for
the Shure E5c. These custom molds are made from your actual ears to insure a
perfect fit. This would also mean better sound and increased comfort.
While i am only reviewing the standard plugs, those with a few extra dollars can
seek out custom moldings from companies such as Sensaphonics (312-432-1714,
www.sensaphonics.com).
According to them "Because of our high quality standards, Sensaphonics has been chosen by Shure Incorporated to be the designer and manufacturer of custom, silicone ear molds that fit over your universal
e1 or e5 earphones. An audiologist in your area will take ear impressions, send them to us and we will customize your
E1 or E5c with an add-on silicone sleeve." As a side note, the E5 and E5c are sold in different places and the E5c
includes an attenuator for portable devices, whereas the E5 does not. And
with that out of the way, let us get to the listening.

Hearing Is BelievingWhile i had previously enjoyed music (albeit briefly) through
the e5, was impressed enough to get a review sample delivered to my home. These
were not your typical units and wanted to further my experience. Upon receiving
the E5 i was so eager that they immediately went into my ears after selecting
the appropriate size of earpiece. What the...??? They sounded horrible! Bright
highs, lacking bass and very little dynamics. Did i pick the wrong earpiece
as this can make a big difference? There are small, medium, and large Fit pieces in
the "Fit Kit" plus a foam insert as pictured below. Note, the Zip case
is also included with the e5 for easy storage and holds both the e5 and extra
fittings.

Experience has taught me well as i did indeed have the right
sized plastic ear fit piece. Hmm... Perhaps they need time to break in? Easy
enough as i placed the CD by Prodigy titled Fat Of The Land in my Sony
D-25 on endless repeat. This CD is great at thoroughly breaking in
units as you have plenty of fast-paced rhythms, deep bass, and highs. After a
few days i decided to give the Shure E5c monitors another listen.

It was as though an exorcism had been made! Be gone you Satanic
sounds! Gone were the aggressive highs and lack of dynamics as my ears were
treated to a wonderfully balanced frequency response with an abundance of micro
dynamics. After quite some time with the Sony D-25, the E5c also saw time with my
Roland V-Session "state-of-the-art" electronic drum set. If you feel
your system is good, or any system for that matter, try using it as
amplification/monitoring of electronic drums. This is a brutal test for virtual
any system as the demands are extremely high in speed, dynamics, and
headroom.

If you desire transient speed, it is virtually impossible to
beat an in-ear monitor. If you want to hear nearly every single detail in a
recording/sound, in-ear is quite probably the best way to go. Even the
Sennheiser HD600 may to be lacking as compared to in-ear monitoring. As for outside
noise isolation... in-ear monitoring my friends. This is also why a vast amount of
professional musicians reply on this type of sound monitoring. An added benefit
is that it virtually eliminates stage monitors blasting out sound at high volume
levels, and the hearing damage occurred through employing such devices. Anyway,
back to what truly matters... the music!

Musically YoursThe Shure E5c have a wonderful smoothness; yet will not hide the
defects of your upstream gear. In other words, if there is the slightest error
in frequency response or a lack of smoothness, you will know about it immediately. There is nowhere for distortion or other errors to hide.
This is akin to the difference of using a normal Zeiss microscope unit as compared
to a top-line electron microscope. The Sennheiser HD600 are very good,
though not the very last word in resolution as compared to the Shure E5c. The way
bass is produced and felt is very different when you go from a normal system to
headphones... or to in-ear monitors. Within a normal loudspeaker-based system your
ears hear the notes as your body feels the bass. With the Sennheiser HD600 the
large units vibrate and you still have a feeling of bass, yet to a lesser extant
of normal loudspeakers. With in-ear monitoring you need to adjust to no real
vibrating at all. Bass notes simply happen without much feeling of external
vibration. Not everyone will find this type of experience desirable, so please
keep this in mind.

The uppermost frequencies are very smooth when the upstream
equipment dictates. The midrange is very precise as the e5 easily unravels
layers upon layers of sound. My point here is that the e5 are neither
forgiving (like the HD600) nor lacking in revealing every detail. Garbage
in = garbage out. The lower frequencies may take some music lovers a bit of time
to understand, as it is not like normal dynamic driver headphones or
loudspeakers. Yes, the bass is very fast, tight and deep. Must also point out
that simply using difference Fit pieces can alter the way the uppermost and
lowermost frequencies sound. Fortunately the e5 comes with three pairs of
different Fit piece sizes and also foam inserts. Since each ear is different and
swapping out the Fit piece is fast and easy, try the medium size first and go
from there. As i have smallish ear canals, the small worked best for me.

Am basically going to avoid the whole discussion of binaural
recordings and the like, as those are covered in our partnered publication's
sister website www.binaural.com
by all around great guy John Sunier. Yes, binaural recordings with the Shure E5c
are wonderful and free audio samples are available by
clicking here.

ConclusionIn the end the combination of Sony D-25 with the Shure E5c are
the single most amazing portable "system" i have heard. You get a
combination of extreme resolution, very even overall frequency response and
wonderful harmonics. The dynamics may seem a tad bit more expanded than normal
as you will hear nearly every volume change, including those on the
mastering board while making the recording. As mentioned earlier, these are akin
to having an electron microscope! If you can not find a Sony D-25, the D-555 can
also be found, if a bit lacking in smoothness and resolution of the D-25, yet
still leagues ahead of the plastic rubbish sold in stores today. If you demand
your iPod, the Shure E5c may bring you many steps closer to the true potential of
the unit over more mainstream monitoring devices.

StorageEver the wise marketing company combined with courting nearly
every online audiophile publication i know of is Slappa (www.slappa.com).
After talking to many people, they realized that the public wanted a hard
(yet not overly ridged) case and a place to store the CD and also the
liner notes. Therefore the folks at Slappa designed "DOUBLE-DIP" pockets
that hold both the CD and also the liner notes in separate stacked slots (see
graphic below).

An added benefit of the Slappa cases, including their smaller
offering (32 HardBody), is that the Sony D25 easily fits inside. This makes my traveling
life easy as the CDs and Sony D-25 are secure within the Slappa 32 HardBody as
the Shure e5 include their own case. Slappa makes other cases that hold from the
aforementioned 32 to a nice library of 192 discs. Having a few examples/sizes
here, i can attest to their solid construction and smart design.

So there you have it my friends. While the Sony D-25 is a rare
bird, your hard work will be greatly paid off in knowing you have what is
probably the best portable compact disc player ever made. The Shure E5c in-ear
monitors serve not just for portable duties, but also within your home system
while the Slappa disc case will store your traveling collection. Of course in the
end what really matters is that you...